Pyrophoric alloy.



: TED s'rawnnr onrion.

x Specification of Letters Patent.

Patented Nov. 27, 1906.

Application filed November 27, 1903. Serial No. 182,884

To all whom, it may concernq Be it known that I, CARL AUER VON WELs-EACH, chemist, of IV Wiedner-Hauptstrass'e 5?,aVienna, and ofRastenfeld, Austria,

Hungary, have invented certain new and useful Im rovements in PyrophoricAlloys, of which t e following isa specification.

My invention relates to a manufacture of metallic alloys havingpyrophoric action and their application to the purposes of ignition andillumination.

It has been variously assertedthat the rare earth metals have theroperty of giving off particles that are se -igniting in the air whenscratched with a hard sharp substance. Experiments which I have made inthis di rection show, however, thalrthese statements are erroneous, as Ihave found that the rare earth metals when ure do not show this peculiarpro erty-an'd that the non-ignition of the said etached particles undercertain circumstances rather indicate the urity of the earth metal.Ihave discovered, owever,

that the rare earth metal cerium becomes pyrophoric if alloyed withcertain other metals, in particular iron. Even with a very smallpercentage ofiron the alloy gives off of pyrophoric energy.

' be entirely replaced by rapidity sparks onbeing rubbed with a file. Asthe percentage of iron is increased the sparking ecomes more intense,eventually becoming .a shower and resulting me very luminous de-'velopment of light. With about thirty per cent. of iron the alloyattains its maximum It is in this condition so sensitive that it' onlyrequires tobe slightly touched with a file to give ofi an intense showerof sparks, though somewhat less luminous than with a lower percentage ofiron. 3

In these allo s the iron can be partially replaced by nic el or cobalt;butif the iron have erty is considerab diminished.

small particles separated by friction, t e

and without any development of heat appre v ighiting in-a very promptand reliab e manner combustible gases mixed with-- air.

The preparation of the said alloys can readily carried out if ironin afinely-divi these the pyro horic' urning of. which takes place withexceeding ciable to the hand, are ob. able of.

be ded condition be added to the cerium while the l latter is still in amolten state in the decomposing cell (wherein it has been reduced fromits com ound in the well-known manner) and whi e the passage of theelectric current through the molten metal is still maintained. The ironunder these circumstances readily dissolves in the cerium and the alloyproduced can be run into molds under the exclusion of air. I

The sparking can be produced not only by abrasion, but also byconcussive action.

It will be understood that instead of using cerium alone as the metal tobe alloyed the iron or its equivalent I may use in conjunction therewithone or more of the other:

metals usually known as rare earth metals, such as lanthanum and thelike; but for the purposes of this invention the presence of the ceriumis relied upon as essential for the development of the pyrophoricproperties of the the resultant alloy. In other words, it is rac- Vtically essential for the production 0 the commercial resultscontemplated by this invention that where any other of the rare earthmetals is used in making u the iron alloy it shall be associated withcerium and that un-' less cerium is present the pyrophoric prop- /ertiesof the alloy are insufficient for the uses herein contemplated.Commercial lanthanum, for instance, is frequently associated. 1

with cerium as an incident to its mode of manufacture, inasmuch as it isgenerally pro-- duced from sources containing cerium, an it is thepresence of the cerium in the final alloy that is e sential in everycase to the invention herein claimed. I

What I claim is- I 1. A-pyrophoric alloy, containing ceriusm,

alloyed with iron; substantially as and for the purposes described.

'2. A pyrophoric alloy, containing cerium alloyed with thirtyper cent.--of iron; substantially as and for the p oses described.

.In witness whereof I have ereunto signed my name, this 10th day ofNovember: 1903, in the presence of two subscribing witnesses.

CARL AUER VON WELSliACH Witnesses: ALVESTO S. Hoetm,

LEML. Hmrs.

